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Heparin Induced Thrombocytopenia (HIT)

Blood Sciences Test


2 x Serum tubes

Special Instructions

A special form “Platelet Immunology 3d” obtainable from the Blood Transfusion department (ext 2467) needs to be completed by the requesting Clinician.

The “4t’s” evaluation score should have been completed prior to making any request. For current version please refer to http://www.bcshguidelines.com/index.html (Click “View guidelines”).

A score of 6-8 is associated with a high probability of HIT

A score of 4-5 is associated with an intermediate probability

A score of 0-3 means there is a low probability

They require Patient Full Name, DOB,NHS number,Hospital Number and/or address. Samples must be labelled, dated and signed by the sample taker at time of collection. Patient ID labels are not allowed on Transfusion samples.

Please see Transfusion Policy for information on sample labelling requirements

Investigation must be sanctioned by a Consultant Haematologist

Factors affecting results

Samples should be transported at ambient temperature and delivered to the H&I laboratory in Filton in a timely manner preferably within 24 hours of collection and no later than 72 hours.

Reference Ranges

Not applicable

Test Usage

To determine whether or not heparin therapy is causing thrombocytopaenia.:


Test performed at the National Health Service Blood and Transplant (NHSBT) H&I department, Filton, Bristol

Turnaround time

1-2 days

Clinical Advice

Clinical advice is available from the Haematology Medical team (contact RD&E switchboard on 01392 411611)


Specimen Labelling Procedure
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